Interconnected semiconductor devices

ABSTRACT

Semiconductor layer and conductive layer formed on a flexible substrate, divided into individual devices and interconnected with one another in series by interconnection layers and penetrating terminals.

INTERCONNECTED SEMICONDUCTOR DEVICES

The Government of the United States of America has rights in thisinvention pursuant to Subcontract ZB-4-03056-2 awarded by the UnitedStates Department of Energy.

This is a division of co-pending application Ser. No. 07/131,416, filedDec. 10, 1987, now U.S. Pat. No. 4,873,201.

BACKGROUND OF THE INVENTION

1. Field of the Invention.

The present invention relates to interconnecting in series a sequence ofsemiconductor devices and, more particularly, to interconnecting inseries an array of photovoltaic devices.

Solar cells represent a source of electrical energy based on aninexhaustable "fuel", with the operation of such devices beingnonpolluting. The primary difficulty in the use of a photovoltaic devicebased electrical energy source has been economics. The costs offabricating solar cells have heretofore prevented widespread use of suchcells for providing electrical energy, and have confined such use tospecial situations where the fabrication economics do not make the usethereof prohibitive.

A major improvement in economics follows from the use of amorphoussilicon as the semiconductor material in the solar cells rather thancrystalline silicon. Crystalline silicon is an indirect-band-gapmaterial meaning that a lattice phonon is required to participate in theabsorption process with an incident photon. Thus, crystalline siliconabsorbs electromagnetic radiation relatively weakly. Amorphous silicon,on the other hand, is a direct-band-gap material of an effectivelylarger bandgap in which the incident photon can be absorbed without anyinteraction being required of lattice phonons. As a result, an amorphoussilicon layer of a given thickness can absorb as much electromagneticradiation from the sun as can a crystalline silicon layer many times itsthickness, typically in a thickness ratio of fifty to one, even thoughat a somewhat shorter wavelength range. Thus, very much thinner films ofamorphous silicon can be used and still absorb the same amount ofincident radiation energy, a structure which reduces the cost of a solarcell considerably.

The use of amorphous silicon, however, has problems of its own. The purematerial has a low resistivity and is insensitive to the addition ofdoping impurities because there are relatively large numbers ofelectronic energy states occurring at energy values that would be inapproximately an energy state gap in crystalline silicon. Thus, thisregion of amorphous silicon is often referred to as a "pseudogap" and islocated in the mobility gap between extended energy states. Theseadditional electronic states arise because of the presence of smallvoids throughout the amorphous silicon which give rise to variousdangling bonds and distorted bonds between silicon atoms.

This situation, which would otherwise make amorphous silicon a poorcandidate for forming solar cells, is greatly improved by introducing asubstantial concentration of hydrogen into the amorphous silicon,usually to the extent that hydrogen represents many atomic percent ofthe resulting material. This hydrogenated amorphous silicon is usuallydesignated as a-Si:H. This improvement follows from hydrogen formingbonds with the silicon to eliminate dangling bonds, and also breakingdistorted bonds, through the hydrogen bonding to the silicon atoms.These effects, and others, lead to material which has a relatively welldefined energy gap and in which the semiconductor properties can becontrolled by the doping of further impurities. That is, n-typeconductivity material can be provided by doping with phosphorus, andp-type conductivity material can be provided through doping with boron,as examples. This situation permits the forming of p-n junctionstructures or p-i-n structures ("i" meaning intrinsic or near intrinsicsemiconductor material) so that amorphous silicon structures subject toincident electromagnetic radiation can be operated as photovoltaic solarcells.

Such solar cells are usually formed in a large array of individual cellsto capture large amounts of incident sunlight. However, because p-njunctions or p-i-n layer arrangements formed in doped a-Si:H yieldphotovoltaic cells with open circuit voltages measuring several tenthsof a volt, there is a desire to electrically interconnect at least somecells in the array in series to provide a greater output voltage.Typically, such cells are formed as a "sandwich-like" structure on asubstrate with such cells having, as a general matter, two conductivelayers with a semiconductor material layer therebetween where one of theconductive layers is directly on the substrate. The semiconductor layerhas a p-n junction or p-i-n layer arrangement therein more or lessparallel to the conductive layers. One of the conductive layers istransparent to pass incident electromagnetic radiation to thesemiconductor material layer (the substrate will also be transparent ifit directly supports the transparent conductive layer). There isdifficulty with this arrangement in electrically interconnecting theconductive layer adjacent the substrate in one cell, because of it beingcovered by the other "sandwich" layers, to the conductive layer of anadjacent cell on the opposite side of the semiconductor material layertherein.

An arrangement is desired for effecting such interconnections which iseconomical and reliable. Such interconnections must be made in a processcompatible with fabricating large volumes of solar cells.

SUMMARY OF THE INVENTION

The present invention provides a plurality of semiconductor devices on asubstrate each having a penetrating terminal extending from a conductivelayer through a semiconductor material layer where it is in electricalcontact with a conductive interconnection layer formed acrossintervening material in a separating space between adjacentsemiconductor devices to electrically contact the semiconductor materiallayer of the adjacent device, with said penetrating terminal beingspaced apart from such separating spaces. A device is formed,electrically interconnected to the next device, from a semiconductormaterial layer supported on a conductive layer on a substrate bydividing these two layers to form a plurality of semiconductor devices,forming an electrical insulating material in separating spaces providedby such dividing, and forming a penetrating terminal in each devicethrough the semiconductor material layer to the conductive layer on thesubstrate. An upper conductive layer as an interconnection layer can beinitially present and divided over the region of dividing of thesemiconductor material and other conductive layer, with the material forthe penetrating terminal being in contact with an adjacent semiconductordevice interconnection layer. Alternatively, the interconnection layercan be provided afterward extending from the penetrating terminal ontothe intervening material in the separating space and into electricalcontact with the semiconductor material layer of the adjacent device.The penetrating terminal is formed by applying a laser beam to metalcomprising material placed on the semiconductor material layer of eachsemiconductor device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A through 1H show results of steps in the process of fabricatingthe device of the present invention,

FIGS. 2A through 2D show results of an alternative for some of the stepsin the process of FIGS. 1A through 1H for fabricating the device of thepresent invention,

FIGS. 3A through 3F show results of steps in an alternative process offabricating the device of the present invention,

FIGS. 4A and 4B show results of an alternative for some of the steps inthe process of FIGS. 3A through 3F for fabricating the device of thepresent invention, and

FIGS. 5A through 5C show results of an alternative for some of the stepsin the process of FIGS. 3A through 3F for fabricating the device of thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1A shows a portion of an initially prepared layer structure, 10,from which solar cell semiconductor devices are to be formed. Layeredstructure 10 can be prepared by well known methods and so itsfabrication process is not set forth here.

Layered structure 10 has a substrate, 11, formed of polyimide having athickness of approximately 2.0 mils. Formed on substrate 11 is a layer,12, of aluminum or aluminum alloy having a thickness of approxiately 0.1μm with a highly reflective top surface. Layer 12 supports asemiconductor material layer, 13, at its lower major surface of a 0.5 μmthickness formed of a-Si:H and doped, using well known methods, toprovide a p-n junction or a p-i-n layer arrangement which isapproximately parallel to layer 12. Layer 12 is in electrical contactwith the lower major surface of semiconductor material layer 13 on oneside of this p-n junction or a p-i-n layer arrangement. (A furtherpossiblity would be to eliminate a physical structure-basedsemiconductor junction in semiconductor layer 13 and have thetransparent layer to be provided be in electrical contact with a side oflayer 13 for forming a Schottky-barrier therewith.)

No representation of the p-n junction present in the figures of thisapplication is provided, as it would unnecessarily complicate them.Further, these figures are not to actual scale, and proportions havebeen chosen for clarity rather than actual physical representation.

FIG. 1B shows the results of dividing conductive layer 12 andsemiconductor layer 13 in layered structure 10 into a plurality of layerportions each of which will form a solar cell semiconductor device. Thedivision is made by a YAG laser of a 532 nm wavelength scribing acrosslayer structure 10 at a traverse speed of 180 in/min. with an outputpower of 250 mw to remove material where the beam impinges down topolyimide substrate 11. The laser provides a satisfactory beam forleaving a separating space, 14, between each of the layer portions ofapproximately 50 μm in width.

The dividing of layers 12 and 13 simultaneously has been found to beespecially effective with these two layers being provided on flexiblepolyimide substrate 11. If metal layer 12 is divided withoutsemiconductor layer 13 thereon, portions of the metal splatter and forma deposited debris in detrimental locations. Attempts to clean away suchdebris, by ultrasonic cleaning for instance, damage the remainingportions of layer 12 probably because of substrate 11 being flexible.Semiconductor layer 13 prevents such splattering during the laserdividing process.

Layered structure 10 in FIG. 1B is formed as an elongated arrangement tothe right and the left of what is shown so that a plurality of openings14 to the right and left of the one shown and perpendicular to the planeof the paper are also formed. These openings lead to a plurality ofsolar cell semiconductor devices being formed. The elongated arrangementcan be stored in rolls before or after subsequent process steps to makeconvenient the handling of large numbers of joined semiconductordevices.

Thereafter, through the use of screen or ink-jet printing, a polymer"ink" is applied to fill opening 14 and to cover a portion of the uppermajor surface of semiconductor material layer 13 near and on either sideof opening 14. This polymer ink material forms an intervening electricalinsulating material, 15, in opening 14 which serves to furtherelectrically isolate adjacent solar cell semiconductor devices from oneanother. A suitable polymer for this purpose which can be printed inthis manner is Advance ADE-Series air-dry polymer.

Simultaneously, or alternatively, either before or after, additionalpolymer material is printed at another location on the upper majorsurface of semiconductor material layer 13 to form a surface protectionlayer, 16, spaced apart from intervening material 15 formed in opening14. The same polymer material used for intervening material 15 issuitable for polymer 16. Polymers 15 and 16 are both printed as a stripperpendicular to the plane of the view shown in FIG. 1C and more or lessparallel to one another. The width of these strips on the upper majorsurface of semiconductor material layer 13 is approximately 16 mils butmay be less.

Between intervening material 15 and surface protecting material 16 thereis next printed, again by screen printing methods, a silver filledpolymer ink strip, 17. Thus, the extent of strip 17 on the upper majorsurface of semiconductor material layer 13 is limited by the presence ofstrips 15 and 16, as shown in FIG. 1D permitting convenient screenprinting thereof in rapid, large volume fabrication operations. Asuitable material for silver filled polymer ink 17 is Amicon C-225Series inks.

Again using a 532 nm YAG laser, a laser beam is directed along silverfilled polymer ink 17 at 2.0 in/sec with an output power of 350 mwcausing this material to heat substantially and be driven downwardthrough semiconductor material layer 13 to make contact with aluminumconductor layer 12 supporting layer 13 to thereby form a conductivepenetrating terminal now designated 17' in FIG. 1E. Thus, aninterconnection means to conductive support layer 12 is made availableat the upper major surface of semiconductor material layer 13 spacedapart from the separating space filled with intervening material 15.Because semiconductor material layer 13 is amorphous, the presence of aconductor 17' in electrical contact with this layer on either side ofany p-n junction or intrinsic layer contained therein is not a shortingproblem. The resistivity of the amorphous silicon material, even doped,is so great laterally that only a very small portion of the junction isin effect shorted by penetrating terminal 17'.

Thereafter, a very thin layer, 18, of approximately 200 Å thickness oftin oxide is sputter deposited on the upper device surface at the stageshown in FIG. 1E as a conductive, diffusion barrier. The deposition isfrom a 97% Sn/3% Sb metal alloy target and done with substrate 11 andthe semiconductor devices thereon passing from roll to roll through theoperation at 20 ft/min resulting in a layer with a bulk resistivity ofabout 7×10⁻² Ω-cm. A further layer, 19, of 2000 Å of indium tin oxide isthen sputter deposited on the layer of tin oxide with the result shownin FIG. 1F. This deposition uses a 95% In/5% Sn metal alloy target withthe tin oxide covered semiconductor devices on substrate 11 passingthrough the operation at 1 ft/min. The resulting film has a bulkresistivity of about 5.6 Ω-cm×10⁻³. Together films 18 and 19 have asheet resistance of

05 approximately 28 Ω/square. Layer 18 prevents indium from reachingsemiconductor material layer 13 to thereby adversely affect theelectrical characteristics of this layer. Layer 19 is more conductivethan is layer 18 and so is used to form the bulk of interconnectionlayer 18,19.

These two layers, 18 and 19, are transparent to portions of the spectrumof sunlight which are significantly absorbed by semiconductor materiallayer 13 so that electromagnetic radiation from the sun coming fromabove in FIG. 1F will reach semiconductor layer 13. The thickness oflayers 18 and 19 together are chosen so that they are approximatelythree-quarters of a wavelength in thickness for the peak wavelength inthe visible spectrum. This is an antireflection measure to assure thatthere is good transfer of incident electromagnetic radiation from thesun to semiconductor material layer 13 for absorption therein.

Finally, a 532 nm YAG laser is again used to divide transparentinterconnection layers 18 and 19 by directing the laser beam along thelayers at 300 in/min with an output power of 160 mw to form a gap, 20,therein over surface protecting strip 16. Again, gap 20 as formed isapproximately 50 μm wide. Surface protecting material 16 protectssemiconductor material layer 13 from being damaged by the laser beam.Surface protecting layer 16 could be eliminated if the laser beam waschosen to have enough energy to divide layers 18 and 19 without damagingsemiconductor layer 13, and if silver filled polymer ink 17 can beprinted sufficiently accurately on the surface of semiconductor layer 13without the blocking effect provided by strip 16. The final result isshown in FIG. 1G where the right-hand portion of interconnection layers18 and 19 on the right side of gap 20 is in electrical contact withpenetrating terminal 17' and extends onto intervening material 15 acrossthe separating space 14 in which material 15 has been placed and on tothe upper major surface of semiconductor material layer 13 in theadjacent solar cell semiconductor device. This interconnection layerportion ends on the surface protection strip 16 formed in that devicejust as the portion of layers 18 and 19 to the left of gap 20 in FIG. 1Aends on strip 16.

Other alternatives in this process would be to dispense with interveningmaterial 15 in separating space 14 and, alternatively, subject thestructure of FIG. 1B to an oxidizing atmosphere to form an electricallyinsulative oxide on the exposed ends of aluminum layer 12. Presently,the use of polymer insulating material in opening 14 is preferred. Also,rather than using a silver filled polymer ink for strip 17 and sopenetrating terminal 17', a metal strip can be sputter depositedalternatively and subjected to the laser beam at a linear series ofpoint locations along the metal strip to drive that metal throughsemiconductor material layer 13 to be in electrical contact with supportlayer 12. A typical metal arrangement for strip 17 would be to have afirst layer of chromium in a thickness of 50 Å, followed by 7500 Å ofsilver, and completed with another 400 Å of chromium

Another view of the resulting device of FIG. 1G is shown in FIG. 1H. Thearrangement for interconnection conductor 18,19 is more clearly shown inextending from a penetrating terminal 17' in one solar cellsemiconductor device on to intervening material 15 and over to the uppermajor surface of the semiconductor material layer 13 in the adjacentsolar cell semiconductor device. The p-i-n junction or pn junction insemiconductor layer 13 has been shown in this view as a dashed line inthat layer in each device.

An alternate set of completion steps for the process of FIGS. 1A through1H is shown beginning in FIG. 2A, a set which begins after the stepshown in FIG. 1C. In these steps, the providing and diffusing of thefilled polymer is interchanged with the providing of the transparentinterconnection layer.

Thus, transparent interconnection layer 18',19' is shown on the uppermajor surface of semiconductor material layer 13 over both interveningmaterial 15 and surface protection strip 16 in FIG. 2A. Then, silverfilled polymer ink strip 17" is screen printed on the upper surface oflayer 19' over intervening material 15 extending on either side thereoffor a distance including being sufficient to be partly over surfaceprotection strip 16. This result is shown in FIG. 2B.

A laser beam, again from a 532 nm YAG laser, is translated in a linealong polymer ink strip 17" at the location above the separation betweenintervening material 15 and surface protective strip 16 at 2.0 in/secusing an output power of 350 mw to heat this material sufficiently todrive it at this location through both transparent interconnection layer18',19' and semiconductor material 13 and into electrical contact withconductive layer 12 to again form conductive penetrating terminal 17'".This outcome is shown in FIG. 2C where the upper portion of terminal17'" continues to be spread over a greater area of transparentinterconnection layer 18',19' to thereby reduce the electricalresistance between terminal 17'" and layer 18',19'.

Thereafter, transparent interconnection layer 18',19' is again dividedby use of a laser to form gap 20 over surface protection strip 16. Thereis thereby formed a series of transparent electrodes each (other than anend unit) over and in electrical contact with the upper major surface ofa separated portion of semiconductor layer 13 and in electrical contactwith penetrating terminal 17'" of an adjacent such separated portion.This is shown in FIG. 2D.

An alternative way of fabricating such a solar cell semiconductor deviceis shown in FIG. 3A. The initial layered structure for this alternativeis now designated 10' because of an added layer being initially presentbeyond those shown in layered structure 10 in FIG. 1A. That is, atransparent interconnection layer 18",19" is now shown on the uppermajor surface of semiconductor material layer 13. Semiconductor materiallayer 13 again has a p-n junction or p-i-n layer arrangement (or, asbefore, neither if a Schottky-barrier is used) extending therethroughparallel to support layer 12 (not shown).

Once again, a division of layers 12 and 13 must be made to provideseparate solar cell semiconductor devices. This division of these layerscan be done simultaneously with dividing layers 18",19", followed byproviding additional width to the opening in layers 18",19", or,alternatively, transparent interconnection layer 18",19" can be dividedprior to dividing layers 12 and 13. This latter option is chosen in theexample shown in FIG. 3B. There, an opening, 21, is shown dividingtransparent interconnection layer 18",19" which would be done in severalplaces in the elongated layered structure 10' to the right and left ofthat shown in FIG. 3B, the opening running perpendicular to the plane ofthe view in FIG. 3B. Opening 21 can be formed by using a water-jet etchmoving along the material, or by a screen-printed etch paste. Such anopening might extend 50 to 100 mils in width.

Thereafter, a separating space is extended by use of a laser beam intosemiconductor material layer 13 and conductive support layer 12 fromopening 21 just as before to thereby form opening 14 in these layers.The results are shown in FIG. 3C.

The first option of dividing layers 12 and 13 simultaneously withtransparent interconnection layers 18",19" is shown in FIGS. 4A and 4Bwhich can be substituted for FIGS. 3B and 3C in the fabrication processof FIGS. 3A through 3F. The result of these layers in FIG. 3A beingdivided simultaneously by a laser beam is shown in FIG. 4A. As indicatedabove, this is followed by opening wider layers 18",19" about thelaser-provided opening therein which is shown in FIG. 4B.

A further alternative for the fabrication process of FIGS. 3A through 3Fis shown in FIGS. 5A through 5C which build on the structures shown inFIGS. 1A and 1B. These together are substituted for FIGS. 3A through 3C.The structure of FIG. 1B has an ink deposit, 22, screen-printed thereonas shown in FIG. 5A. This ink is a solvent-washable one which "outgases"very little, one such ink being supplied by the Minnesota Mining andManufacturing Company under the designation TB 16900.

Thereafter, film 18" and 19" are deposited as before. This is shown inFIG. 5B. The structure at this point again is redesignated as 10".

The portion of transparent interconnection layer 18'",19'" over inkdeposit 22 can then be removed by using a suitable solvent to dissolveink deposit 22 under that portion of layer 18'",19'" Such a solvent ismethyl ethyl ketone which, applied on layer 18'",19'", penetrates thatlayer to reach deposit 22 to dissolve it. The portion of layer 18'",19'"thereover is also carried away to result in the structure of FIG. 5C.

The use of the laser beam to divide layers 12 and 13 has been shownprior to providing ink deposit 22 in connection with FIGS. 1A, 1B and 5Athrough 5C. Alternatively, the laser beam could be used after theprovision of deposit 22 (deposited only on the upper major surface ofsemiconductor layer 13 so that the portion extending below this surfacein FIGS. 5A and 5B would not be there and layers 12 and 13 would becontinuous in these figures) and layers 18'" and 19'". The beam would beused to simultaneously divide layer 18'",19'", deposit 22 and layers 12and 13. This method would prevent the debris from this process beingdeposited on layer 13 and provides for its being washed away by the useof the solvent to remove deposit 22 and the portions of layer 18'",19'"thereover. Of course, the laser beam in this situation couldalternatively be used to divide layers 12 and 13 simultaneously afterthe solvent has removed deposit 22 and the portion of layer 18'",19'"thereover.

Any of these alternatives for dividing layers 12 and 13 with thetranparent interconnecting layer 18",19" or 18'",19'" provided prior tosuch dividing is again followed by providing electrical insulatingintervening material 15 in opening 14. The polymer material usedpreviously for this purpose is again satisfactory in this step and canonce more be provided using screen printing. The result can be seen inFIG. 3D. As before, a strip of this polymer material 16 is provided,typically by screen printing methods, on the upper major surface ofsemiconductor material layer 13. Where this strip served as a surfaceprotection and flow blocking strip previously, it now primarily servesas a flow blocking strip.

Strip 16, again being parallel to the strip of intervening material 15,serves to block any flow of silver filled polymer ink material providedfor the penetrating terminal from reaching the left-hand portion oftransparent interconnection layer 18",19". Such a silver filled polymerink, now designated 17"", is shown screen printed onto the upper majorsurface of semiconductor material layer 13 to the left of interveningmaterial 15, onto intervening material 15, onto the upper major surfaceof semiconductor material 13 in the adjacent solar cell semiconductordevice to the right of material 15, and onto the portion of transparentinterconnection layer 18",19" of the adjacent semiconductor device tothe right of material 15. The result is shown in FIG. 3E.

Silver filled polymer ink 17"" makes electrical contact with thisright-hand portion of transparent interconnect layer 18",19" serving asthe transparent interconnection layer for the adjacent semiconductordevice. Note that there need be no concern about any of transparentinterconnection layer 18",19" to the left of material 15 coming intocontact with silver filled polymer ink 17"" because of the presence ofstrip 16 to block any such flow.

Finally, a laser beam is directed onto a portion of silver filledpolymer ink 17"" just as before to thereby drive this material throughsemiconductor material layer 13 and into electrical contact withconductive support layer 12, as shown in FIG. 3F. Silver filled polymerink 17"" has now been redesignated 17'"" as it serves both to form apenetrating terminal through semiconductor material layer 13 to supportlayer 12, as just stated, and to interconnect this penetrating terminalwith the transparent interconnect layer 18",19" in the adjacent solarcell semiconductor device. Thus, once penetratingterminal-interconnection means silver filled polymer ink material 17""has been deposited and the penetrating terminal portion therefrom formedby the laser beam to provide penetrating terminal-interconnection means17'"", nothing further need be done to complete the solar cells (otherthan possible protective steps, convenience arranging steps, packagingsteps, etc.) as all electrical interconnections in series betweenadjacent solar cell semiconductor devices have been completely formed.

Although the present invention has been described with reference topreferred embodiments, workers skilled in the art will recognize thatchanges may be made in form and detail without departing from the spiritand scope of the invention.

What is claimed is:
 1. An interconnected array of semiconductor devices,said array comprising:a plurality of semiconductor devices arrayed on asubstrate each spaced apart from each one adjacent thereto in that saidplurality of semiconductor devices by a separating space having thereinintervening material means, said plurality of semiconductor devices eachhaving therein a support layer of a first conductive material and acorresponding layer of semiconductor material with first and secondmajor surfaces such that said semiconductor material layer is separatedat said second major surface thereof from said substrate by itscorresponding support layer, said plurality of semiconductor deviceseach having a penetrating terminal therein of a second conductivematerial spaced apart from any said separating space and extending fromsaid support layer therein through said semiconductor material layertherein to emerge at said first major surface of that said semiconductormaterial layer which remains a unitary electrically conductive body withthat said penetrating terminal therethrough; and a plurality ofinterconnection layer means comprising at least a third conductivematerial which is transparent to visible light, said plurality of saidinterconnection layer means each being in electrical contact with saidfirst major surface of said semiconductor material layer of one of saidplurality of semiconductor devices and each further being in electricalcontact with a said penetrating terminal where it emerges from saidfirst major surface of said semiconductor material layer in an adjacentone of said plurality of semiconductor devices by having a selected oneof that interconnection layer means and that penetrating terminal extendover said intervening material means across a said separating space toto thereby form an electrical interconnection, said third conductivematerial having an outer surface on a side thereof opposite saidsemiconductor material layer which is free of any of said interveningmaterial means.
 2. The apparatus of claim 1 wherein each of saidplurality of interconnection layer means, in electricallyinterconnecting said first major surface of said semiconductor layer inone of said plurality of semiconductor devices ends before coming intoelectrical contact with said penetrating terminal thereof.
 3. Theapparatus of claim 2 wherein each of said plurality of interconnectionlayer means, in electrically interconnecting said first major surface ofsaid semiconductor material layer in one of said plurality ofsemiconductor devices ends on a protective insulating material formed onsaid first major surface of said semiconductor material layer in thatone of said plurality of semiconductor devices.
 4. The apparatus ofclaim 3 wherein each of said plurality of interconnection layer means,in electrically interconnecting a said penetrating terminal, also endson said protective insulating material formed on said first majorsurface of said semiconductor material layer in that one of saidplurality of said semiconductor device in which said penetratingterminal is formed, with each of those ones of said plurality ofinterconnection layer means ending in common on a said protectiveinsulating material being spaced apart from one another.
 5. Theapparatus of claim 1 wherein each said penetrating terminal is of amaterial comprising metal.
 6. The apparatus of claim 1 wherein each saidintervening material means is an electrical insulating material.
 7. Theapparatus of claim 6 wherein said intervening material is a polymermaterial.
 8. The apparatus of claim 1 wherein said substrate is amaterial which is an electrical insulating material.
 9. The apparatus ofclaim 8 wherein said substrate is a polyimide material.
 10. Theapparatus of claim 1 wherein each said semiconductor material comprisesamorphous, hydrogenated silicon doped to have a p-n junction therein.11. The apparatus of claim 10 wherein each said semiconductor materiallayer has a p-n junction therein with said support layer correspondingto that said semiconductor material layer being in electrical contactwith said second major surface of that said semiconductor material layeron one side of said p-n junction, and with each of said plurality ofinterconnection layer means in electrical contact with said first majorsurface of that said semiconductor material layer being in such contacton an opposite side of said p-n junction.
 12. The apparatus of claim 1wherein said semiconductor material layer comprises amorphous,hydrogenated silicon doped to have a p-type conductivity layer and ann-type conductivity layer separated by an intrinsic layer.
 13. Theapparatus of claim 1 wherein each said support layer comprises a metalmaterial.
 14. The apparatus of claim 1 wherein each said interconnectionlayer is transparent to visible light.
 15. The apparatus of claim 14wherein each said interconnection layer comprises indium tin oxide.